/*
** $Id: liolib.c $
** Standard I/O (and system) library
** See Copyright Notice in lua.h
*/

#define liolib_c
#define LUA_LIB

#include "lprefix.h"


#include <ctype.h>
#include <errno.h>
#include <locale.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "lua.h"

#include "lauxlib.h"
#include "lualib.h"




/*
** Change this macro to accept other modes for 'fopen' besides
** the standard ones.
*/
#if !defined(l_checkmode)

/* accepted extensions to 'mode' in 'fopen' */
#if !defined(L_MODEEXT)
#define L_MODEEXT "b"
#endif

/* Check whether 'mode' matches '[rwa]%+?[L_MODEEXT]*' */
static int l_checkmode (const char *mode) {
    return (*mode != '\0' && strchr("rwa", *(mode++)) != NULL &&
            (*mode != '+' || ((void)(++mode), 1)) &&  /* skip if char is '+' */
            (strspn(mode, L_MODEEXT) == strlen(mode)));  /* check extensions */
}

#endif

/*
** {======================================================
** l_popen spawns a new process connected to the current
** one through the file streams.
** =======================================================
*/

#if !defined(l_checkmodep)
/* By default, Lua accepts only "r" or "w" as mode */
#define l_checkmodep(m) ((m[0] == 'r' || m[0] == 'w') && m[1] == '\0')
#endif


#if !defined(l_popen)  /* { */

#if defined(LUA_USE_POSIX) /* { */

#define l_popen(L,c,m)  (fflush(NULL), popen(c,m))
#define l_pclose(L,file) (pclose(file))

#elif defined(LUA_USE_WINDOWS) /* }{ */

#define l_popen(L,c,m)  (_popen(c,m))
#define l_pclose(L,file) (_pclose(file))

#else    /* }{ */

/* ISO C definitions */
#define l_popen(L,c,m)  \
   ((void)c, (void)m, \
   luaL_error(L, "'popen' not supported"), \
   (FILE*)0)
#define l_pclose(L,file)  ((void)L, (void)file, -1)

#endif    /* } */

#endif    /* } */

/* }====================================================== */


#if !defined(l_getc)  /* { */

#if defined(LUA_USE_POSIX)
#define l_getc(f)  getc_unlocked(f)
#define l_lockfile(f)  flockfile(f)
#define l_unlockfile(f)  funlockfile(f)
#else
#define l_getc(f)  getc(f)
#define l_lockfile(f)  ((void)0)
#define l_unlockfile(f)  ((void)0)
#endif

#endif    /* } */


/*
** {======================================================
** l_fseek: configuration for longer offsets
** =======================================================
*/

#if !defined(l_fseek)  /* { */

#if defined(LUA_USE_POSIX) /* { */

#include <sys/types.h>

#define l_fseek(f,o,w)  fseeko(f,o,w)
#define l_ftell(f)  ftello(f)
#define l_seeknum  off_t

#elif defined(LUA_USE_WINDOWS) && !defined(_CRTIMP_TYPEINFO) \
   && defined(_MSC_VER) && (_MSC_VER >= 1400) /* }{ */

/* Windows (but not DDK) and Visual C++ 2005 or higher */
#define l_fseek(f,o,w)  _fseeki64(f,o,w)
#define l_ftell(f)  _ftelli64(f)
#define l_seeknum  __int64

#else    /* }{ */

/* ISO C definitions */
#define l_fseek(f,o,w)  fseek(f,o,w)
#define l_ftell(f)  ftell(f)
#define l_seeknum  long

#endif    /* } */

#endif    /* } */

/* }====================================================== */



#define IO_PREFIX "_IO_"
#define IOPREF_LEN (sizeof(IO_PREFIX)/sizeof(char) - 1)
#define IO_INPUT (IO_PREFIX "input")
#define IO_OUTPUT (IO_PREFIX "output")


typedef luaL_Stream LStream;


#define tolstream(L) ((LStream *)luaL_checkudata(L, 1, LUA_FILEHANDLE))

#define isclosed(p) ((p)->closef == NULL)


static int io_type (lua_State *L) {
    LStream *p;
    luaL_checkany(L, 1);
    p = (LStream *)luaL_testudata(L, 1, LUA_FILEHANDLE);
    if (p == NULL)
        luaL_pushfail(L);  /* not a file */
    else if (isclosed(p))
        lua_pushliteral(L, "closed file");
    else
        lua_pushliteral(L, "file");
    return 1;
}


static int f_tostring (lua_State *L) {
    LStream *p = tolstream(L);
    if (isclosed(p))
        lua_pushliteral(L, "file (closed)");
    else
        lua_pushfstring(L, "file (%p)", p->f);
    return 1;
}


static FILE *tofile (lua_State *L) {
    LStream *p = tolstream(L);
    if (isclosed(p))
        luaL_error(L, "attempt to use a closed file");
    lua_assert(p->f);
    return p->f;
}


/*
** When creating file handles, always creates a 'closed' file handle
** before opening the actual file; so, if there is a memory error, the
** handle is in a consistent state.
*/
static LStream *newprefile (lua_State *L) {
    LStream *p = (LStream *)lua_newuserdatauv(L, sizeof(LStream), 0);
    p->closef = NULL;  /* mark file handle as 'closed' */
    luaL_setmetatable(L, LUA_FILEHANDLE);
    return p;
}


/*
** Calls the 'close' function from a file handle. The 'volatile' avoids
** a bug in some versions of the Clang compiler (e.g., clang 3.0 for
** 32 bits).
*/
static int aux_close (lua_State *L) {
    LStream *p = tolstream(L);
    volatile lua_CFunction cf = p->closef;
    p->closef = NULL;  /* mark stream as closed */
    return (*cf)(L);  /* close it */
}


static int f_close (lua_State *L) {
    tofile(L);  /* make sure argument is an open stream */
    return aux_close(L);
}


static int io_close (lua_State *L) {
    if (lua_isnone(L, 1))  /* no argument? */
        lua_getfield(L, LUA_REGISTRYINDEX, IO_OUTPUT);  /* use default output */
    return f_close(L);
}


static int f_gc (lua_State *L) {
    LStream *p = tolstream(L);
    if (!isclosed(p) && p->f != NULL)
        aux_close(L);  /* ignore closed and incompletely open files */
    return 0;
}


/*
** function to close regular files
*/
static int io_fclose (lua_State *L) {
    LStream *p = tolstream(L);
    int res = fclose(p->f);
    return luaL_fileresult(L, (res == 0), NULL);
}


static LStream *newfile (lua_State *L) {
    LStream *p = newprefile(L);
    p->f = NULL;
    p->closef = &io_fclose;
    return p;
}


static void opencheck (lua_State *L, const char *fname, const char *mode) {
    LStream *p = newfile(L);
    p->f = fopen(fname, mode);
    if (p->f == NULL)
        luaL_error(L, "cannot open file '%s' (%s)", fname, strerror(errno));
}


static int io_open (lua_State *L) {
    const char *filename = luaL_checkstring(L, 1);
    const char *mode = luaL_optstring(L, 2, "r");
    LStream *p = newfile(L);
    const char *md = mode;  /* to traverse/check mode */
    luaL_argcheck(L, l_checkmode(md), 2, "invalid mode");
    p->f = fopen(filename, mode);
    return (p->f == NULL) ? luaL_fileresult(L, 0, filename) : 1;
}


/*
** function to close 'popen' files
*/
static int io_pclose (lua_State *L) {
    LStream *p = tolstream(L);
    errno = 0;
    return luaL_execresult(L, l_pclose(L, p->f));
}


static int io_popen (lua_State *L) {
    const char *filename = luaL_checkstring(L, 1);
    const char *mode = luaL_optstring(L, 2, "r");
    LStream *p = newprefile(L);
    luaL_argcheck(L, l_checkmodep(mode), 2, "invalid mode");
    p->f = l_popen(L, filename, mode);
    p->closef = &io_pclose;
    return (p->f == NULL) ? luaL_fileresult(L, 0, filename) : 1;
}


static int io_tmpfile (lua_State *L) {
    LStream *p = newfile(L);
    p->f = tmpfile();
    return (p->f == NULL) ? luaL_fileresult(L, 0, NULL) : 1;
}


static FILE *getiofile (lua_State *L, const char *findex) {
    LStream *p;
    lua_getfield(L, LUA_REGISTRYINDEX, findex);
    p = (LStream *)lua_touserdata(L, -1);
    if (isclosed(p))
        luaL_error(L, "default %s file is closed", findex + IOPREF_LEN);
    return p->f;
}


static int g_iofile (lua_State *L, const char *f, const char *mode) {
    if (!lua_isnoneornil(L, 1)) {
        const char *filename = lua_tostring(L, 1);
        if (filename)
            opencheck(L, filename, mode);
        else {
            tofile(L);  /* check that it's a valid file handle */
            lua_pushvalue(L, 1);
        }
        lua_setfield(L, LUA_REGISTRYINDEX, f);
    }
    /* return current value */
    lua_getfield(L, LUA_REGISTRYINDEX, f);
    return 1;
}


static int io_input (lua_State *L) {
    return g_iofile(L, IO_INPUT, "r");
}


static int io_output (lua_State *L) {
    return g_iofile(L, IO_OUTPUT, "w");
}


static int io_readline (lua_State *L);


/*
** maximum number of arguments to 'f:lines'/'io.lines' (it + 3 must fit
** in the limit for upvalues of a closure)
*/
#define MAXARGLINE 250

/*
** Auxiliary function to create the iteration function for 'lines'.
** The iteration function is a closure over 'io_readline', with
** the following upvalues:
** 1) The file being read (first value in the stack)
** 2) the number of arguments to read
** 3) a boolean, true iff file has to be closed when finished ('toclose')
** *) a variable number of format arguments (rest of the stack)
*/
static void aux_lines (lua_State *L, int toclose) {
    int n = lua_gettop(L) - 1;  /* number of arguments to read */
    luaL_argcheck(L, n <= MAXARGLINE, MAXARGLINE + 2, "too many arguments");
    lua_pushvalue(L, 1);  /* file */
    lua_pushinteger(L, n);  /* number of arguments to read */
    lua_pushboolean(L, toclose);  /* close/not close file when finished */
    lua_rotate(L, 2, 3);  /* move the three values to their positions */
    lua_pushcclosure(L, io_readline, 3 + n);
}


static int f_lines (lua_State *L) {
    tofile(L);  /* check that it's a valid file handle */
    aux_lines(L, 0);
    return 1;
}


/*
** Return an iteration function for 'io.lines'. If file has to be
** closed, also returns the file itself as a second result (to be
** closed as the state at the exit of a generic for).
*/
static int io_lines (lua_State *L) {
    int toclose;
    if (lua_isnone(L, 1)) lua_pushnil(L);  /* at least one argument */
    if (lua_isnil(L, 1)) {  /* no file name? */
        lua_getfield(L, LUA_REGISTRYINDEX, IO_INPUT);  /* get default input */
        lua_replace(L, 1);  /* put it at index 1 */
        tofile(L);  /* check that it's a valid file handle */
        toclose = 0;  /* do not close it after iteration */
    }
    else {  /* open a new file */
        const char *filename = luaL_checkstring(L, 1);
        opencheck(L, filename, "r");
        lua_replace(L, 1);  /* put file at index 1 */
        toclose = 1;  /* close it after iteration */
    }
    aux_lines(L, toclose);  /* push iteration function */
    if (toclose) {
        lua_pushnil(L);  /* state */
        lua_pushnil(L);  /* control */
        lua_pushvalue(L, 1);  /* file is the to-be-closed variable (4th result) */
        return 4;
    }
    else
        return 1;
}


/*
** {======================================================
** READ
** =======================================================
*/


/* maximum length of a numeral */
#if !defined (L_MAXLENNUM)
#define L_MAXLENNUM     200
#endif


/* auxiliary structure used by 'read_number' */
typedef struct {
    FILE *f;  /* file being read */
    int c;  /* current character (look ahead) */
    int n;  /* number of elements in buffer 'buff' */
    char buff[L_MAXLENNUM + 1];  /* +1 for ending '\0' */
} RN;


/*
** Add current char to buffer (if not out of space) and read next one
*/
static int nextc (RN *rn) {
    if (rn->n >= L_MAXLENNUM) {  /* buffer overflow? */
        rn->buff[0] = '\0';  /* invalidate result */
        return 0;  /* fail */
    }
    else {
        rn->buff[rn->n++] = rn->c;  /* save current char */
        rn->c = l_getc(rn->f);  /* read next one */
        return 1;
    }
}


/*
** Accept current char if it is in 'set' (of size 2)
*/
static int test2 (RN *rn, const char *set) {
    if (rn->c == set[0] || rn->c == set[1])
        return nextc(rn);
    else return 0;
}


/*
** Read a sequence of (hex)digits
*/
static int readdigits (RN *rn, int hex) {
    int count = 0;
    while ((hex ? isxdigit(rn->c) : isdigit(rn->c)) && nextc(rn))
        count++;
    return count;
}


/*
** Read a number: first reads a valid prefix of a numeral into a buffer.
** Then it calls 'lua_stringtonumber' to check whether the format is
** correct and to convert it to a Lua number.
*/
static int read_number (lua_State *L, FILE *f) {
    RN rn;
    int count = 0;
    int hex = 0;
    char decp[2];
    rn.f = f;
    rn.n = 0;
    decp[0] = lua_getlocaledecpoint();  /* get decimal point from locale */
    decp[1] = '.';  /* always accept a dot */
    l_lockfile(rn.f);
    do {
        rn.c = l_getc(rn.f);
    }
    while (isspace(rn.c));    /* skip spaces */
    test2(&rn, "-+");  /* optional sign */
    if (test2(&rn, "00")) {
        if (test2(&rn, "xX")) hex = 1;  /* numeral is hexadecimal */
        else count = 1;  /* count initial '0' as a valid digit */
    }
    count += readdigits(&rn, hex);  /* integral part */
    if (test2(&rn, decp))  /* decimal point? */
        count += readdigits(&rn, hex);  /* fractional part */
    if (count > 0 && test2(&rn, (hex ? "pP" : "eE"))) {  /* exponent mark? */
        test2(&rn, "-+");  /* exponent sign */
        readdigits(&rn, 0);  /* exponent digits */
    }
    ungetc(rn.c, rn.f);  /* unread look-ahead char */
    l_unlockfile(rn.f);
    rn.buff[rn.n] = '\0';  /* finish string */
    if (lua_stringtonumber(L, rn.buff))  /* is this a valid number? */
        return 1;  /* ok */
    else {  /* invalid format */
        lua_pushnil(L);  /* "result" to be removed */
        return 0;  /* read fails */
    }
}


static int test_eof (lua_State *L, FILE *f) {
    int c = getc(f);
    ungetc(c, f);  /* no-op when c == EOF */
    lua_pushliteral(L, "");
    return (c != EOF);
}


static int read_line (lua_State *L, FILE *f, int chop) {
    luaL_Buffer b;
    int c;
    luaL_buffinit(L, &b);
    do {  /* may need to read several chunks to get whole line */
        char *buff = luaL_prepbuffer(&b);  /* preallocate buffer space */
        int i = 0;
        l_lockfile(f);  /* no memory errors can happen inside the lock */
        while (i < LUAL_BUFFERSIZE && (c = l_getc(f)) != EOF && c != '\n')
            buff[i++] = c;  /* read up to end of line or buffer limit */
        l_unlockfile(f);
        luaL_addsize(&b, i);
    } while (c != EOF && c != '\n');  /* repeat until end of line */
    if (!chop && c == '\n')  /* want a newline and have one? */
        luaL_addchar(&b, c);  /* add ending newline to result */
    luaL_pushresult(&b);  /* close buffer */
    /* return ok if read something (either a newline or something else) */
    return (c == '\n' || lua_rawlen(L, -1) > 0);
}


static void read_all (lua_State *L, FILE *f) {
    size_t nr;
    luaL_Buffer b;
    luaL_buffinit(L, &b);
    do {  /* read file in chunks of LUAL_BUFFERSIZE bytes */
        char *p = luaL_prepbuffer(&b);
        nr = fread(p, sizeof(char), LUAL_BUFFERSIZE, f);
        luaL_addsize(&b, nr);
    } while (nr == LUAL_BUFFERSIZE);
    luaL_pushresult(&b);  /* close buffer */
}


static int read_chars (lua_State *L, FILE *f, size_t n) {
    size_t nr;  /* number of chars actually read */
    char *p;
    luaL_Buffer b;
    luaL_buffinit(L, &b);
    p = luaL_prepbuffsize(&b, n);  /* prepare buffer to read whole block */
    nr = fread(p, sizeof(char), n, f);  /* try to read 'n' chars */
    luaL_addsize(&b, nr);
    luaL_pushresult(&b);  /* close buffer */
    return (nr > 0);  /* true iff read something */
}


static int g_read (lua_State *L, FILE *f, int first) {
    int nargs = lua_gettop(L) - 1;
    int n, success;
    clearerr(f);
    if (nargs == 0) {  /* no arguments? */
        success = read_line(L, f, 1);
        n = first + 1;  /* to return 1 result */
    }
    else {
        /* ensure stack space for all results and for auxlib's buffer */
        luaL_checkstack(L, nargs+LUA_MINSTACK, "too many arguments");
        success = 1;
        for (n = first; nargs-- && success; n++) {
            if (lua_type(L, n) == LUA_TNUMBER) {
                size_t l = (size_t)luaL_checkinteger(L, n);
                success = (l == 0) ? test_eof(L, f) : read_chars(L, f, l);
            }
            else {
                const char *p = luaL_checkstring(L, n);
                if (*p == '*') p++;  /* skip optional '*' (for compatibility) */
                switch (*p) {
                case 'n':  /* number */
                    success = read_number(L, f);
                    break;
                case 'l':  /* line */
                    success = read_line(L, f, 1);
                    break;
                case 'L':  /* line with end-of-line */
                    success = read_line(L, f, 0);
                    break;
                case 'a':  /* file */
                    read_all(L, f);  /* read entire file */
                    success = 1; /* always success */
                    break;
                default:
                    return luaL_argerror(L, n, "invalid format");
                }
            }
        }
    }
    if (ferror(f))
        return luaL_fileresult(L, 0, NULL);
    if (!success) {
        lua_pop(L, 1);  /* remove last result */
        luaL_pushfail(L);  /* push nil instead */
    }
    return n - first;
}


static int io_read (lua_State *L) {
    return g_read(L, getiofile(L, IO_INPUT), 1);
}


static int f_read (lua_State *L) {
    return g_read(L, tofile(L), 2);
}


/*
** Iteration function for 'lines'.
*/
static int io_readline (lua_State *L) {
    LStream *p = (LStream *)lua_touserdata(L, lua_upvalueindex(1));
    int i;
    int n = (int)lua_tointeger(L, lua_upvalueindex(2));
    if (isclosed(p))  /* file is already closed? */
        return luaL_error(L, "file is already closed");
    lua_settop(L, 1);
    luaL_checkstack(L, n, "too many arguments");
    for (i = 1; i <= n; i++)  /* push arguments to 'g_read' */
        lua_pushvalue(L, lua_upvalueindex(3 + i));
    n = g_read(L, p->f, 2);  /* 'n' is number of results */
    lua_assert(n > 0);  /* should return at least a nil */
    if (lua_toboolean(L, -n))  /* read at least one value? */
        return n;  /* return them */
    else {  /* first result is false: EOF or error */
        if (n > 1) {  /* is there error information? */
            /* 2nd result is error message */
            return luaL_error(L, "%s", lua_tostring(L, -n + 1));
        }
        if (lua_toboolean(L, lua_upvalueindex(3))) {  /* generator created file? */
            lua_settop(L, 0);  /* clear stack */
            lua_pushvalue(L, lua_upvalueindex(1));  /* push file at index 1 */
            aux_close(L);  /* close it */
        }
        return 0;
    }
}

/* }====================================================== */


static int g_write (lua_State *L, FILE *f, int arg) {
    int nargs = lua_gettop(L) - arg;
    int status = 1;
    for (; nargs--; arg++) {
        if (lua_type(L, arg) == LUA_TNUMBER) {
            /* optimization: could be done exactly as for strings */
            int len = lua_isinteger(L, arg)
                      ? fprintf(f, LUA_INTEGER_FMT,
                                (LUAI_UACINT)lua_tointeger(L, arg))
                      : fprintf(f, LUA_NUMBER_FMT,
                                (LUAI_UACNUMBER)lua_tonumber(L, arg));
            status = status && (len > 0);
        }
        else {
            size_t l;
            const char *s = luaL_checklstring(L, arg, &l);
            status = status && (fwrite(s, sizeof(char), l, f) == l);
        }
    }
    if (status) return 1;  /* file handle already on stack top */
    else return luaL_fileresult(L, status, NULL);
}


static int io_write (lua_State *L) {
    return g_write(L, getiofile(L, IO_OUTPUT), 1);
}


static int f_write (lua_State *L) {
    FILE *f = tofile(L);
    lua_pushvalue(L, 1);  /* push file at the stack top (to be returned) */
    return g_write(L, f, 2);
}


static int f_seek (lua_State *L) {
    static const int mode[] = {SEEK_SET, SEEK_CUR, SEEK_END};
    static const char *const modenames[] = {"set", "cur", "end", NULL};
    FILE *f = tofile(L);
    int op = luaL_checkoption(L, 2, "cur", modenames);
    lua_Integer p3 = luaL_optinteger(L, 3, 0);
    l_seeknum offset = (l_seeknum)p3;
    luaL_argcheck(L, (lua_Integer)offset == p3, 3,
                  "not an integer in proper range");
    op = l_fseek(f, offset, mode[op]);
    if (op)
        return luaL_fileresult(L, 0, NULL);  /* error */
    else {
        lua_pushinteger(L, (lua_Integer)l_ftell(f));
        return 1;
    }
}


static int f_setvbuf (lua_State *L) {
    static const int mode[] = {_IONBF, _IOFBF, _IOLBF};
    static const char *const modenames[] = {"no", "full", "line", NULL};
    FILE *f = tofile(L);
    int op = luaL_checkoption(L, 2, NULL, modenames);
    lua_Integer sz = luaL_optinteger(L, 3, LUAL_BUFFERSIZE);
    int res = setvbuf(f, NULL, mode[op], (size_t)sz);
    return luaL_fileresult(L, res == 0, NULL);
}



static int io_flush (lua_State *L) {
    return luaL_fileresult(L, fflush(getiofile(L, IO_OUTPUT)) == 0, NULL);
}


static int f_flush (lua_State *L) {
    return luaL_fileresult(L, fflush(tofile(L)) == 0, NULL);
}


/*
** functions for 'io' library
*/
static const luaL_Reg iolib[] = {
    {"close", io_close},
    {"flush", io_flush},
    {"input", io_input},
    {"lines", io_lines},
    {"open", io_open},
    {"output", io_output},
    {"popen", io_popen},
    {"read", io_read},
    {"tmpfile", io_tmpfile},
    {"type", io_type},
    {"write", io_write},
    {NULL, NULL}
};


/*
** methods for file handles
*/
static const luaL_Reg meth[] = {
    {"read", f_read},
    {"write", f_write},
    {"lines", f_lines},
    {"flush", f_flush},
    {"seek", f_seek},
    {"close", f_close},
    {"setvbuf", f_setvbuf},
    {NULL, NULL}
};


/*
** metamethods for file handles
*/
static const luaL_Reg metameth[] = {
    {"__index", NULL},  /* place holder */
    {"__gc", f_gc},
    {"__close", f_gc},
    {"__tostring", f_tostring},
    {NULL, NULL}
};


static void createmeta (lua_State *L) {
    luaL_newmetatable(L, LUA_FILEHANDLE);  /* metatable for file handles */
    luaL_setfuncs(L, metameth, 0);  /* add metamethods to new metatable */
    luaL_newlibtable(L, meth);  /* create method table */
    luaL_setfuncs(L, meth, 0);  /* add file methods to method table */
    lua_setfield(L, -2, "__index");  /* metatable.__index = method table */
    lua_pop(L, 1);  /* pop metatable */
}


/*
** function to (not) close the standard files stdin, stdout, and stderr
*/
static int io_noclose (lua_State *L) {
    LStream *p = tolstream(L);
    p->closef = &io_noclose;  /* keep file opened */
    luaL_pushfail(L);
    lua_pushliteral(L, "cannot close standard file");
    return 2;
}


static void createstdfile (lua_State *L, FILE *f, const char *k,
                           const char *fname) {
    LStream *p = newprefile(L);
    p->f = f;
    p->closef = &io_noclose;
    if (k != NULL) {
        lua_pushvalue(L, -1);
        lua_setfield(L, LUA_REGISTRYINDEX, k);  /* add file to registry */
    }
    lua_setfield(L, -2, fname);  /* add file to module */
}


LUAMOD_API int luaopen_io (lua_State *L) {
    luaL_newlib(L, iolib);  /* new module */
    createmeta(L);
    /* create (and set) default files */
    createstdfile(L, stdin, IO_INPUT, "stdin");
    createstdfile(L, stdout, IO_OUTPUT, "stdout");
    createstdfile(L, stderr, NULL, "stderr");
    return 1;
}

